Joining a union or creating one is one of the most subversive things one can do in this day and age. Propaganda for unions is very effective at leveraging the class schism in favour of workers/socialism.

Just don't a union that advocates creating large weaponry or represents law enforcement/servants of the state.

Proper unionising makes capitalists piss their pants. I have read a ton about politics (to my detriment – rip mental health) and it seems to really give you the most bang for your buck.